Fixatie o of correction



o 3, .1929. E. KLM-1N :1' AL Re. 17,453

THERIOS TAT! G SWITGH Original Filed Jan. 21. 1922 3 Shasta-Shut 1 OCL 3; 1929- E. KLAHN er AL Re 17,453

THERIIOS TAT I C SW1 TCH Original Filed Jan. 21. 1922 5 Sheets-Smet 2 OCt 8, 1929 E. KLAHN er Al. Re. 17,453

THERIOSTATIC SWI TCH Original Filed Jan.21 1922 3 Sheets-Sheet 5 Sum/tom Reissued Oct. 1929 UNITED STATES PATENT orf-'ica EMIL KLAHN AND FRED L. MULLEN, F NEW VERNON, NEW JERSEY THERMOSTATIC SWITCH Original No. 1,594,304, dated July 27, 1926, Serial No. 530,977, led January 21, 1922. Application for reissue led April 9, 1928. Serial No. 268,708.

The object of our invention is to provide a thermostatic control for an electric heating device, intended more particularly for household and for other uses, which shall possess certain novel features andadvantages, and which shall be more durable, less likely to get out of order, and more economical than similar devices now in use for such purposes.

Tothis end our invention consists First, in providing electric heating devices with an automatic or thermostatic cut-off of new and peculiar type.

Second, in providing electric heating devices with circuit closers and breakers without causingv a spark, or spark gap.

Third, in providing electric heating devices with means whereby the desired different degrees of heat ma be obtained with a single heating coil, which does not become incandescent.

Fourth, in providing electric heating devices with a new type of switch by which the operator may vary the degrees of heat supplied by a single coil.

Fifth, in providing electric heating devices with means whereby the effective heat is continued for an unusually long period after the energizing current is cut oil'.

In the accompanying drawings we have shown one form of our improved heating device in which all these objects are attained, and in which:-

Figure 1 is a top plan;

4 Fig. 2 is a vertical section on line 2-2 of Fig. 1;

Fig. 3 is a looking in the direction of the arrows;

Figs. 4, 5,'6, and 7 are details of the automatic or thcrmostatic circuit closer or cuto oii,-and showing the same in normal con tact,-(Fig. 4)-in expanded position under heat,-(Fig. 5)-on the verge of cut-olin under pressure from below,-(Fig. 6)-and out ot contact (Fig. 7), the cut-oft having sprung labove the normal or neutral line, as hereinafter explained.

Fig. 8 is a side elevation of the rack of insulating material, on which the heating wire is coiled;

horizontal section on line 3--3' Fig. 9 is a bottom plan, thereof, to show the wiring of a single coil of heating wire.

Same letters indicate similar parts in the different drawings.

A, is the hollow body ofthe electric heating iron, of suitable size and strength. B, is a removable top or lid, held to the body by screws, a, a, a, and provided with binding posts b, b. C, is a removable handle, held to the lid B, by screws c, c, and protected by the insulations d, d. An oil hole e, is provided through the lid, and closed by a suitable set screw.

The most important element in the said heating iron is the automatic cut-oil', which,

as shown, consists primarily of a resilient, expansible disc, or snapping plate or mem brane, D, sprung into a suitable groove in a holding ring E, in such way that the material ot' the membrane must, when left free, bulge either upwardly or downwardly from its centre of suspension. When pressure is applied to repress this bulge, the membrane recedes reluctantly toward what may be called the neutral line, being the horizontal lcentre of its suspension, `but the slightest movement beyond that dead centre, causes the membrane to snap vigorously to its upper or lower bulging position.

By taking advantage of this instantaneous snapping action we are able to break the electric contact and cut off the supply of electric current so suddenly and so completely that nov spark occurs from the electric current usually fed on household wires. As an added protection against the creation of a spark-gap, we iill the interior of the iron body A with a non-conducting oil to a depth sullicient to submerge the contact point, as hereafter explained. The fing E, may be integral with the lid B, as shown, or separate and held thereto by screws f, f.

On the under side of the membrane is secured an insulating plate F, on which are mounted the contact points g, g, in proper relation to contacts g', g constituting the terminals ofthe brushes h, h, through which current is derived from the binding posts b', b which latter support said brushes, the same being secured thereto in the well known'manner as indicated.

Contact between the points g, g and brushes h, k is normally maintained by means of the coiled spring z' on the adjusting post Gr, which is accessible from the outside of the iron and turned by hand into any desired position to determine the amount of current (heat) at which the cut-ofi' shall act to break the circuit. The post G carries a pointerlc, adapted to travel over the scale I, on which are to be marked such points or degrees of heat as may be taken as stops, generally, lthree, to witzmaximum heat permitted,-minimum heat used, and zero. It will be readily understood that when the pointer la is turned to the maximum heat, the spring z' will be compressed to its normal maximum and will therefore press the membrane D downward with its full force. This position is shown in Fig. 4.

Then the membrane expands downwardly under the heat received by the iron from the electric current, its expansive force will bulge `the membrane further downward into the position shown in Fig. 5. When this happens, the coiled spring will have been released from part of the pressure of the post G and will appear partly relaxed as shown in said Fig. 5.

When, as hereafter explained, the heat of the iron approaches the maximum allowed for the cuthof, and upward counter pressure is created against the under side of the membrane and this counter` pressure, increasing with the heat, forces the membrane u wardly against the coiled spring, slowly to t e position shown in Fig. 6, the neutral line, and then with a sudden snap, upward to the position shown in Fig. 7. y

Owing to the inherent tendency of two opposing contacts to slightly cohere during the passage therethrou h of an electric current of the wattage suc as exists in the circuit of an ordinary electric heating iron, the live contacts g', g of the brushes L, h will, during the slow upward movement of the membrane toward its neutral position temporarily cohere to live contacts g, g with the consequence that the brushes k, k will bedragged slightly upward beyond their normal or free position shown in Fig. 7, into an abnormal or uppermost position shown in Fig. 6, thus insuring intimate engagement of the opposing contacts until substantially the instant that the snapping action of the membrane occurs. Thereupon the membrane moves into its extreme upper position shown in Fig. 7 and the contacts g', g being now free, recede down wardly into their normal free position also shown in Fig. 7.

During the aforesaid slow upward movement of the mebrane toward the neutral line, the contact portions g', g' of the brushes h, will, because of the resilience of the brushes themselves, move upward from the position shown in Fig. 5 to a position which will enable them to maintain contact with the contacts g, g until the central portion of the membrane almost reaches the neutral line though it is not essential, because of the aforesaid additional dragging action, that the free position of the contacts g', g on the brushes shall be quite so accurately positioned in such close proximity with respect to contacts g, g when'the latter are in their uppermost position, provided that such contacts, g', g in their free position are not so far distant as t-o preclude contact between brushes g', g and g, g during the upward movement of the diaphragm up to the time that the diaphragm substantially attains momentarily its imaginaryneutral line position.

The instant the membrane, during its upward movement, approximates the neutral line, it will snap vigorously into the upward bulgingV position shown in Fig. 7 and as it snaps it will effect the sudden break or separationbetween the contacts g, g and g', g irrespective of the atoresaid slight tendency of the same to cohere. As this separation occurs the brushes it, h will recede slightly from the position to which they have been dragged', as shown in Fig. 6, to their normal free position shown in Fig. 7.

The diaphragm will remain in its new upwardly bulging position until the cooling of the iron, following the aforesaid separation of the contacts and the interruption of the flow of current through the heating coil progresses to such an extent that the abnormal expanding bulge-power of the snapping membrane, as well as the pressure of the oil vapors upon the under side of the said membrane or diaphragm is radually reduced and soon a point `of equilirium is reache'd between the downward pressure of the spring and the upward pressure exerted both.by the heated vapors and the upwardly bulging tendency of the heated membrane. Until this point is reached the diaphragm remains in its sprung or uppermost position shown in Fig. 7 but immediately thereafter, owing to the further cooling of the vapors by the radiation and conduction of heat from the inner chamber containing said oil vapors, the diaphragm will slowly or reluctantly recede from its uppermost position toward the neutral or in this case, its center line. Meanwhile the brush contacts g, g' having, as previously stated, receded into their normal or free position shown in Fig. 7, the two contacts will remain separated. As soon, however, as the diaphragm D reaches the neutral line it will, due to its inherent snapping action and under the influence of the spring, suddenly or vigorously again snap, as before, but to its lower bulging position and then the upper contacts g, g will simultaneously snap into engagement with the lower contact g', g of the brushes h, h, withthe consequence that no deleterious arcing between the contacts occur when operating on the ordinar house lighting circuits of 110 A. C. or 120 C. voltage.

The iron as illustrated is provided with a coil frame which, as shown in Figs. 2, 8 and 9, consists of a table-like structure of non-conducting composition H, supported by a sort of bridge-like formation, best shown in Fig. 9 through which the coil entering and departing by the binding posts, Z, Z is threaded in any desired configuration. The binding posts Z, Z are connected by the wire m (see Fig. 2) to the contact points g, g. This single coil element or coil-frame is designed to rest upon the bottom of the hollow body A as shown in Fig. 2, and may, if desired, beattached to the under side of the lid B, by screw-posts, n, n, (Fig. 2) so as to be easily removable with said lid, or may be entirely disconnected therefrom. lVhen so disconnected, the coil-frame is adapted to be used in any electric iron the interior of which is large enough to receive the same.

The third important element in the electric heating iron as illustrated consists in the bath of non-conducting non-inflammable, and somewhat volatile oil, in which the coil-frame is immersed to a level high enough to covery the contact-points g, g and the membrane D, when in its normal downwardly bowed position shown in Fig. 2. This oil, of course, gets heated by the wire coil, threaded through the bridge-work of the coil-frame, and communicates this heat to the body A. But, also, and this is an important feature, the oil under the growing heat gives off heated fumes whichby their inherent expansion, exert anupward pressure upon the membrane D, against the resilient force of the coiled spring z'. The quantity of oil, its space for fume expansion, and the power of the coiled spring are so related to each other that, when the desired maximum heat is reached, the expanding pressure of the oil-fumes will force the downwardly bulging membrane D, just back to a level above the neutral line. As soon as this happens, the membrane, as before stated, snaps up into its normal upwardly bulging positioin-due to the upward pressure exerted by the heated vapors and due also tothe fact that the membrane itself is at that time heated enough above its normal temperature which combined to make the expanding bulge-power of the membrane greater than the resilient force of the coiled spring.

The current having been cut off by this action, the iron and its contents will, of course, begin to cool, but the heat of the oil, having no escape, other than through the radiation` of the outer surface of the iron, itself, keeps the ironing surface of the device eciently hot for a much longer period than the iron unaided would remain effective.

The many advantages of our improved thermostatic switch, will, we think, be readily understood without further explanation.

lVe are aware that in the patent to J. Nathan No. 1,224,313 of May 1, 1917, there is disclosed a knife or blade-switch which is adapted to be operated by the expansive force exerted upon a yielding diaphragm or movable plunger and also that in the patent to Abshagen No. 436,864 there is disclosed a movable plunger' element for carrying a contact that is adapted, as a result of the movement of such plunger, to engage a second cooperating 'contact under certain conditions of operations and we therefore do not claim broadly such mechanical movement or an electric iron or yswitch embodying the same in its construction.

lVhile we preferably employ the construction herein described, various modifications within the spirit of the invention may be made Without departing from the scope of the invention as embraced within the terms of the appended claims.

The expression contact elements or contact members is Iused in the claims to denote the elements interposed in the electric circuit which are adapted to be periodically brought into'contact and be separated in response to the movements of the snapping medium and thereby effect the making and breaking of the circuit controlled by the switch.

By the term automatic as used in the claims to qualify applicants thermostatic switch or thermostatic device, applicants intend to restrict the claims to a self-setting thermostatic device or switch, as` distinguished from one where the manual re-setting of the device or switch, after primary operation thereof, is required.

What we claim and desire to obtain by United States Letters Patent is:

1. An automatic thermostatic device, comprising a snapping membrane confined in such a way that a portion thereof is free to bulge under certain conditions of temperature, either upwardly or downwardly with respect to its centre of suspension and adapted to snap vigorously under certain conditions when moved but Vslightly beyond 'a dead centre, a fluid medium confined by said membrane and adapted, when expanded, to exert pressure on one side thereof, an electric` circuit and an electric switch connected to and adapted to be o erated by the sudden movements of said mem rane, said switch including contact elements having snapping make and break actions under the varying conditions of temperature under which the switch operates, said contact elements being` free to maintain engagement with each other, when the circuit is closed therethrough, until the snapping action of the membrane. occurs and also being free, when such circuit is broken, to remain.

separated until a re-snapping action of the 'the major portion of the surface of said membrane and to initiate the movement of the latter out of a rest position, an electric circuit controlled by said switch, contact elements interposed in said circuit, said cont-act elements having both snapping make and break actions under the varying conditions ot temperature under which the switch operates, said contact elements being free to maintain engagement with each other, when the circuit is closed A therethrough, until the snapping action of the membrane occurs and also being free, when such circuit is broken, to remain separated until a re-snapping action of the membrane occurs, su-ch cycle of operations bein entirely automatic in that no intermediate afi justrnent of the mechanism is required during the elapsed interval between the snapping make and break actions, and means for connecting said circuit to an external source of electric current.

3. An automatic thermostatic switch, having snapping means including a snapping diaphragm adapted to assume two different`positions of rest representing hot and cold positions and a heat responsive medium adapted when heated to have extensive contact with said diaphragm and directly exert pressure over the major portion of the surface of said diaphragm to initiate the movement of the latter out of a rest position, an electric circuit( controlled by said switch, contact members interposed in said circuit, said contact members having both snapping make and break actions under the varying conditions of temperature under which the switch operates, said contact elements being free to maintain engagement with each other, whenthe circuit isclosed therethrough, until the snapping action of the diaphragm occurs and also being free, when such circuit is broken, to remain separated until a re-snapping action of the diaphragm occurs, and one of saidcontact elements being movable in consonance with the snappingl diaphragm, during but a portion only of the period of movement of the snapping diaphragm as it moves from its hot to its cold position to effect the breaking of the circuit through the switch, such cycle of operations being entirely automatic in that no intermediate adjustment of the mechanism is required during theelapsed interval between the snapping make and break actions.

4. An automatic snapping thermostatie switch, having a snapping medium adapted to assume two different positions of rest, representing hot and eoldpositions respectively, a heat responsive medium of a diii'erent character from that of said snapping medium directly associated therewith and in immediate proximity thereto, said heat responsive medium being capable as its tem.

perature increases of directly exertin` pressure on the snapping medium and e ecting the slow initial movement thereof out of its cold rest position, an electric circuit adapted to be controlled by said switch, contact elements interposed in said circuit, certain of the cooperating contact elements being opposed to each other and adapted to have snapping make and Vbreak actions in response to the movement of said snapping medium under the varying conditions of temperature at which the switch operates, said Contact elements being free to maintain engagement with each other, when the circuit is closed therethrough, until the snapping action of the snapping medium occurs, and also being free, when such circuit is broken, to remain separated until a re-snapping action of the snapping medium occurs, such cycle of operations being entirely automatic in that no intermediate adjustment of the mechanism is required during the elapsed interval between the snap ing make and break actions, said contact elements being carried by said snapping medium and by an independent support respectively and one of said contact elements being movable in consonance with the snapping medium duringr but a portion only of the period of movement of said snapping medium from its hot rest position to its cold rest position and means for conducting an electric current from an external source to said circuit.

5. An automatic snapping thermostatic switch, having a snapping element adapted to assume two different positions of rest representing hot andcold positions, a heat-responsive medium having a high index of expansion when heated and being closely associated with said` snapping element but differing in its chemical composition and physical properties therefrom, said heatresponsive medium being adapted, when heated, toVV slowly force said snapping element away from its nor'nal cold position to a neutral position, from which later position said snapping element snaps into another position, an electric circuit controlled by said'switch, means for connecting said circuit to anl external source of electric current, said circuit having contact elements interposed therein, certain of said elements beingopposed to each other and adapted to have alternate snapping make and break actions in response to the movement of said snapping element under the varying conditions of temperature at which the Switch operates, said contact elements being free to maintain engagement with each other, when the circuit, is closed therethrough, until the Y snapping action of the sna ping element occurs and also being free, w en such circuit is broken, to remain separated until a re-snapping action of the snapping element occurs, such cycle of operations being entirely automatic in that no intermediate manual adjustment of the mechanism is required during the elapsed interval bet-Ween the snapping make and break actions, and said contact elements being relatively movable with respect to each other and respectively carried by said snapping element and by an independent support, several of said contact elements being movable with respect to said snapping element and being arranged to move in consonance with said snapping element during but a portion only of the period of movement of the latter from its hot position to its cold position to eect the breaking of the aforesaid circuit through the switch.

6. An automatic thermostatie switch, having snapping means including both a snapping membrane adapted to assume two different positions of rest representing hot and cold positions, and a heat responsive medium directly associated therewith in immediate proximity thereto, which heat responsive medium is adapted under certain heat conditions to directly exert pressure over the major portion of the surface of said membrane and to initiate the movement of the latter out of a rest position, an electric circuit controlled by said switch, contact elements interposed in said circuit, said contact elements having bot-h snapping make and break actions under the varying conditions of temperature under which the switch operates, said contact elements being free to maintain engagement with each other, when the circuit is closed therethrough, until the snapping action of the membrane occurs and also being free, when such circuit is broken, to remain separated until a re-snapping action of the membrane occurs, such cycle of operations being y entirely automatic in that no intermediate i adjustment of the mechanism is required during the elapsed interval between the snapping make and break actions, means for connecting said circuit to an external source of electric current and adjusting means for regulating the temperature at which such switch operates.

7. An automatic thermostatic switch, baving snapping means including both a snapping membrance adapted to assume two different positions of rest representing hot and cold positions, and a heat-responsive medium which is adapted under certain heat conditions to slowly force said snapping membrane away from its normal cold condition to a neutral position, from which the latter position said snapping membrane snaps into another position, an electric circuit controlled by said switch, means for connecting said circuit to an external source of electric current, said circuit having contact elements interposed therein, certain of said elements being opposed to each other and adapted to have alternate snapping make and break actions in response to the movement of said snapping element under the varying conditions of temperature at which the switch operates, said contact elements being free to maintain engagement with each other, when the circuit is closed therethrough, until the snapping action of the membrane `occurs and also being free, when such circuit is broken, to remain separated until a ree-snapping action of the membrane occurs, such cycle of operations being entirely automatic in that no intermediate manual adjustment of the mechanism is required during the elapsed interval between the snapping make and break actions and said Contact elements being relatively movable with respect to each other and respectively carried by said snapping element and by an independent support, at least one of said Contact elements being movable with respect to said snapping element and being arranged to move in consonance therewith during but a portion of the period of movement of the latter from its hot to its cold position, the said contact elements being` adapted to maintain engagement with each other during the slow movement of'said diaphragm immediately prior to the breaking of the circuit maintained bylthe engagement of said contacts, essentially as a result of cohesion between the live contacts, which cohesion is suddenly .overcome by the force exerted by thel snapping action of the membrane whereby instant separation of the contacts without deleterious arcing is accomplished.

8. An automatic thermostatic switch, having snapping means including both a snapping membrane adapted to assume two different positions of rest- I'epresenting hot and cold positions, and a heat-responsive medium which is adapted under certain'heat conditions to slowly force said snapping membrane away from its normal cold condition to a neutral position, from which latter position said snapping membrane snaps into another position, an electric circuit controlled by said switch, means for connecting said circuit to an external source of electric current, a plurality of contact elements carried by said membrane and a plurality of opposing contact elements carried by an independent support, the opposing contacts being movable with respect to each other and adapted to have alternate snapping make and break actions in response to the movement 0f Said A, the mechanism is required during the elapsed v perature under which it operates snapping membrane under the varying conditions of rtemperature at which the switch operates, said contact elements being free to maintain engagement with each other, when the circuit is closed therethrough, until the snapping action of the membrane occurs and also being free, when `such circuit is broken, to remain separated until a re-snapping action of the membrane occurs, such cycle of operations being entirel automatic in that no intermediate manualil adjustment of interval between the snapping make and break actions, several of said contact elements being movable with respect to said snapping element and being arranged 'to move in consonance therewith during but a portion of the period of movement of the cuit adapted to be controlled by said switch, such cycle of operations being entirely auto mat-ic in that no intermediate adjustment of the mechanism is required during the elapsed interval between the snapping make and break actions, and means for conducting electric current from an external source to said circuit.

Signed at New Vernon, in the county of Morris and State of New Jersey this 3rd day of April 1928.

EMIL KLAHN. FRED L. MULLEN.

latter from its hot to its cold position, the

said contact elements being adapted to maintain' engagement with each other during the slow movement of said snapping membrane immediately prior to the breaking of the circuit, maintained by the engagement of said contacts, essentially as a result of cohesion between the live contacts, which cohesion is suddenly overcome by the force exerted by the snapping action of the membrane whereby the circuit through the said opposing contacts is broken in a plurality of different places without deleterious arcing.

9. A self-setting automatic, thermostatic switch, having snapping make and break actions under the varying conditions of temand having contact elements so arranged as to be free to maintain intimate contact until substantially the instant the snapping Aaction of the switch occurs and to be held out of contact with each otheriuntil substantially the instant a further re-snapping action of the switch occurs, such cycle of operations being -entirely automatic in that no intermediate adjustment of the mechanism is required during the elapsed interval between the snapping make and break actions, an electric circuit adapted to be 'intr'olled by said switch, means for conducting an electric current from an eX- ternal source to said circuit and adjusting means for regulating the temperature at which such switch operates including a remote control therefor adapted to be manipulated from a location remote Jfrom said contact elements.

10. An automatic, thermostatic switch having contact members so arranged as to be freed to maintain intimate contact until substantially the instant the snapping action of the switch occurs and to be held out of contact with each other until substantially the instant' a further re-snapping action of the switch occurs and including a snapping membrane and a heat-responsive medium directly associated with an in immediate proximity with'said snapping membrane, an electric cir- CERTFCATE OF CORRECTION Reissue Patent No. 17,453. Granted October 8, 1929, to

EMIL KLAHN ET AL.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, line 57, claim l0, for the word "freed" read "free"; line 64, for "an" read "and"; and that the said Letters Patent should be read with these corrections therein 'that the same may conform to the record of the case in the Patent Office.`

Signed and sealed this 29th day of October, A. D. 1929.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

